高中語法專練：ii. it作為形式主語

ii. it作為形式主語

it作為形式主語，無具體意義，真正的主語由動名詞、動詞不定式和主語從句擔任，被后置。

It is difficult to climb a mountain.

爬山是很艱難的。

正常形式：To climb a mountain is difficult.

It is a good habit to do morning exercises.

做早操是個好習慣。

It's important to study English.

學習英語很重要。

It is dangerous playing with fire.

玩火是危險的。

It is no use learning without thinking.

學而不思則罔。

It is wrong arguing with your parents.

和你的父母吵架是錯誤的。

常見句型有：

1. It is necessary (important, easy, difficult, natural, common, interesting, pleasant ...) for sb. to do sth./that ...

It is very important for us to learn English well .

對我們來說學好英語很重要。

2. It is kind (clever, brave, careful, careless, foolish, honest, nice, polite ...) of sb. to do sth.

It is very kind of you to say so . = You are very kind to say so.

你真好這樣說。

3. It is no good (useless, no use, a waste of time) doing sth.

It's no use crying over spilt milk.

牛奶一灑哭也沒用。

It's no harm drinking running water in that area.

在那個地區(qū)喝自來水沒有害處。

4. It is a pity (a shame) that ...（should）....(主語從句表示出乎預料)

It is pity that you didn't see that good film.

你沒看到那部好電影真可惜。

It is a shame that he didn't pass the exam.

他沒有通過考試，真丟人。

5. It is said （reported, believed, thought, announce, estimated) that ...

It is said that he will be late today.

據說他今天會來晚。

6. It is suggested (advised, ordered, requested ...) that ... (should) ... (主語從句用虛擬語氣表達)

It is suggested that the meeting (should) be put off.

有人建議推遲會議。

It was ordered that we (should) arrive there in two hours.

命令要求我們兩小時內到那里。

7. It takes sb. +一段時間+ to do sth.

It took thousands of people many years to build the Great Wall.

建長城花了千百萬人很多年時間。

It will take him three hours to go to Hangzhou by train.

乘火車去杭州要花他三小時的時間。

8. It seems (appears, happens, turns out, occurred to sb.) that ...

It seems that no one knows anything about the matter.

似乎沒一個人知道有關此事的任何情況。

It seemed that things were not as they expected.

似乎情況不像我們預料的那樣。

It appears to me that the report must be true.

在我看來這個報告肯定是真的。

9. It matters/doesn't matter whether ...

It doesn't matter what you say.

你說什么不要緊。

Does it matter if he can't finish the job in time?

如果他不能按時完成這項工作，關系重大嗎？

10. It is uncertain whether ...

It is uncertain whether he's coming.

還不能肯定他是否能來。

11. It is necessary (important, natural, strange ...) that ... (should) ... (主語從句用虛擬語氣)

It is necessary that he (should) remember these words.

他很有必要記住這些話。

12. It is no wonder/an honour that ...

He missed the first bus, so it is no wonder that he was late for the meeting.

他誤了第一班車，因此難怪他開會遲到了。

專項練習

1. _______ is a fact that Global Warming has had influenced human beings' life.

A. There

B. This

C. That

D. It

2. It is wrong _______ treat your mother like that.

A. that you to

B. of you to

C. for you to

D. because you

3. Is _______ necessary to complete the task before National Day?

A. this

B. that

C. it

D. he

4. Does _______ matter if he can't finish the job on time?

A. this

B. that

C. he

D. it

5. He hasn't had any food for two days. _______ that he is so hungry.

A. There is no point

B. There is no need

C. It is no wonder

D. It is no way

6. _______ he has been fired because of his absence for a long time with no reason.

A. It is said that

B. They all said that

C. That is announced that

D. It was reported

7. It is no use _______ books without reading.

A. to buy

B. in buying

C. of buying

D. buying

8. _______ human beings can live on the moon in the next twenty years.

A. There seems impossible

B. This is impossible for

C. It is impossible of

D. It seems impossible that

9. _______ in the school regulation that students should wear school uniforms at school.

A. What is required

B. What requires

C. It is required

D. It requires

10. —How do you know him well?

—_______ that we live in the same neighborhood.

A. It is

B. That is

C. It is because

D. It happens

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